Not Applicable.
Not Applicable.
(1) Field of the Invention
This invention relates to marine vessels and yachts, specifically to vessels providing respite from wave induced accelerations.
(2) Description of Related Art Including Information Disclosed Under 37 CFR 1.97 and 1.98
Vessels, ships, boats and other water craft which float at the surface of the sea are effected by weather conditions in ways that are unwanted. Some vessels rely on wind for motive power and some even use waves for riding and entertainment, but in most instances waves and stormy weather result in unwanted motion or accelerations. Most floating water craft design is involved with ways to lessen the unwanted motion. The records of marine architecture are punctuated with methods to lessen undesirable motion for vessels both moored or navigating. Stabilizing fins and keels have a long history. Actively controlled stabilizing wings came, especially for large passenger ships though not without an economic cost and/or a power consumption penalty. More recently vessels described by the acronym SWATH for xe2x80x98small-water-plane twin hullxe2x80x99 and HYSWAS for xe2x80x98hydrofoil-small-water-plane shipxe2x80x99 have exploited using the relatively-calmer water lying below the surface in which to place some of the buoyancy volume and hydrodynamic-wing surface of the vessel. Vessels described as hydrofoils can lessen wave effect by raising more traditionally shaped hulls so there is less impact with the wave. SWATH, HYSWAS and Hydrofoil designs show effective reduction in undesirable motions and accelerations up to certain sea states. For higher sea states, in most designs and with a relationship to the size of the vessel, the vessels cease to be fully operable. For seas with waves larger than a given sea state their wave-avoidance effectiveness ends when waves impact their superstructure or main accommodation volume. SWATH, HYSWAS and Hydrofoil designs also rely on underwater horizontal wings to control their hydrodynamic flight at a particular depth. Unfortunately ocean-surface-wave effect can extend down to several times the surface wave height and perturb the flight of wings. Without optimally presenting themselves to every eddy of water motion, these wings can induce turbulence, thence drag and vibration to the vessel. By way of examples, consider 1/ winged passenger airline flight in atmospheric thermal or turbulent conditions 2/ that wingless flying bodies are used in aeronautics.
Large size in a vessel can increase its parameters of operation to larger sea states but largeness of vessel is definitely not a universally suitable prerogative. Also some large cargo ships are regularly subject to being broken by the stresses set up by rogue waves, and ocean swells and associated troughs.
However to partly exemplify what is missing from marine vessel architecture and design is to look for the descriptive phrase xe2x80x98Wave Avoidancexe2x80x99, or perhaps more precisely xe2x80x98wave effect avoidancexe2x80x99. This engineer has not been able to find the phrase xe2x80x98Wave Avoidancexe2x80x99 or xe2x80x98wave effect avoidancexe2x80x99 in the prior art. For vessels which in essence have a small waterplane area, all references would appear to refer to a plane of water. As seas get larger most prior art such as SWATH and HYSWAS can have operation limited by impact with waves, and especially as high speed vessels. Hydrofoil vessels can potentially jump from wave to wave with accompanying accelerations. All have to change operations for certain rogue waves. It is as if all have chosen to take on the wrong side of the ocean atmosphere interface in a challenge to deal with large waves while maintaining a smooth trajectory. HSWAS and other hydrofoils require a power input to achieve their lessening of wave effect.
The examples of prior art listed below are limited as none fully compares to the scope of this patent application.
Harding in U.S. Pat. No. 5,544,610 (1996) shows a cargo submarine. As its title implies it is operated as a submarine and requires stabilizers and active rudders for depth control. Its hull is shown as oval and flattened in cross section in the horizontal plane and described as xe2x80x98horizontally hydrofoil shapedxe2x80x99. This geometry together with horizontal stabilizers make it especially susceptibly to surface wave effect and accelerations when operating with a submerged depth of less than approximately three times the surface wave height. It shows no means of default or self stabilization without power except to float at the surface.
Yoshida in U.S. Pat. No. 4,763,596 (1988) describes a type of SWATH vessel with twin submerged hulls and water planes which again require active wing control for their flight in water. These waterplanes are susceptible to perturbation by wave motion. Its large above surface accommodation make it susceptible to accelerations from collision with large or rogue waves.
Similarly Lake in U.S. Pat. No. 803,174, Lang in U.S. Pat. Nos. 3,830,178 and 3,897,744, Schmidt in U.S. Pat. No. 4,552,083 show the requirement for active wing control.
In accordance with the present invention a passage making surface vessel can maintain a relatively smooth trajectory with relatively small changes in attitude or orientation with respect to the horizontal plane. The amount of vessel exposed to the maximum dynamic effect of any size wave is minimized in keeping with a useful access to the atmosphere. Upper surface structure of vessel is minimized in profile and area for interaction with surface wave effect. Lower surface structure of vessel is contoured for least interaction with all components of deeper wave effect and the unnecessary use of wing appendages is avoided. Surface contours of structure tend to favor no water flow direction save parallel to long axis of vessel. Favored-water flow guides vessel on a flight path determined by vessel attitude. Attitude of vessel is controlled by wide separation of center of buoyancy from a purposefully adjusted center of gravity. The underwater surfaces exposed to the lesser wave active water, create viscous dampening of vertical motion. The resulting dynamics on the vessel are to the greater degree controlled by the interaction with that less dynamic non surface water.
It is therefore an object of the present invention to provide a new level of freedom from undesirable motion for all naturally occurring sea states in a floating vessel [of a given size]. This vessel provides accommodation, or accommodation and travel, near the ocean atmosphere interface.
Induced accelerations from surface waves of all sizes including storm waves and rogue waves, are more effectively avoided than in previous art floating vessels of comparable size. This wave effect avoidance is provided whether making passage, drifting or moored. This wave effect avoidance can be provided by default, that is, without using a power source or power input. It is also an object that this floating vessel can change its mode of operation to wet or dry dock and operate in shallow water.
All surface vessels can be moved by the buoyancy in a wave or swell, of their above waterline structure. Breaking waves and crests can impact the vessel and especially structure above the mean waterline. This motion can be amplified into an inefficient and uncomfortable oscillation by further waves. In the WAY the extra buoyancy and profile of above surface structure is small by comparison, and can not provide enough impetus to cause a motion on the scale felt by other surface vessels. As such the WAY can be described as a low reserve buoyancy vessel.
The large and separated into different water depth strata underwater surface area of the WAY restricts any short term fast oscillations that are out of synchronization with the average motion of the whole body of water that the WAY occupies. Horizontal wings (so called stabilizers on many vessels featuring underwater control) that can receive 1/ complex interference and a destabilizing influence from the vertical-component-of-deep-wave motion 2/ vessel-longitudinal drag, are not required. The WAY is a wingless-flying body when making passage in wave-avoidance mode. The structural exterior surfaces normally lying below the mean ocean surface and elongated parallel to the direction of passage, are mostly rounded on a 90 degree cross section. This is to ensure that water passage over these surfaces has generally no favored direction except parallel to the long axis of the WAY.
For motive-power efficiency the WAY contends with a greater wetted surface area than comparable-conventional-surface vessels. However this is offset by the advantages of lower surface-wave-producing resistance.
For embodiments with sailing rigs, xe2x80x98knockdownxe2x80x99 as experienced by more conventional yachts does not have the same implications, as the righting moment for the WAY is exceptionally high when in wave-avoidance mode. Similarly the possibility of capsize as for conventional vessels, is virtually non existent unless the whole body depth of water which the WAY occupies can roll fast enough to overcome this exceptionally large righting moment. The WAY is also engineered as a watertight entity able to suffer water over the deck.
Further objects and advantages will become apparent from a consideration of the ensuing description and accompanying drawings.